Firstly, applicant wishes to incorporate by reference a disclosure document, number 142,050 which was filed Oct. 10, 1985 in the United States Patent and Trademark Office. A copy of this disclosure document has been included in the application papers filed with this application.
This patent application discloses an invention which is an improvement over an invention disclosed in U.S. Pat. No. 3,761,334 to Zondek and the corresponding reissue patent RE. 30,771, dated Oct. 13, 1981.
The Zondek patent and reissue patent disclose a method of protecting the hulls of marine vessels from fouling which includes the application of a thin copper foil to the hull in a plurality of strips. The inventive method is disclosed as being useable with steel, aluminum, wood and fiberglass hulls and the patent discloses the manner in which the hull should be properly prepared before the metallic foil is applied thereto. As disclosed, the foil is applied to the hull through the use of a layer of adhesive between the foil and hull which adheres the foil thereto. Also disclosed is the manner of overlapping of the respective foil strips and a roller device preferably formed of neoprene or other elastomeric material so that it may conform closely to the hull configuration of the vessel and so that it may press the foil into firm contact with the hull throughout the area where the foil is being applied. As disclosed, the roller is preferably coated with a silicone compound or other non-adhesive coating so that it has no tendancies to stick to the foil. The patent discloses the advantages of the adhesive attachment of the foil to the hull and cites examples of these advantages. For example, "In the case of a wood hull, the adhesive provides an additional coating protecting the hull. The adhesive is of a character that remains flexible and retains its adhesiveness for the life of the foil covering."
The following deficiencies are found in the invention disclosed in the above-discussed patent and reissue patent, which deficiencies have necessitated further research into the hull protection art to find better ways of applying a foil and performing other hull protecting techniques to the optimum manner:
(a) If the foil is applied to the boat hull in the exact manner specified in the patent and reissue patent, destructive electro-chemical corrosion will immediately commence when the vessel is placed in the water whether that water be fresh, salt or brackish in nature. This corrosion will eventually lead to the dezincification and eventual failure of bronze through-hull fittings, rudders, propellers, propeller struts and propeller shafts. This corrosion will also cause marine vessel hulls and components made from steel and aluminum to reject any adhesive bonding with copper-nickel anti-fouling metal. At present, this rejection is caused by electrical ions flowing in a path between the more noble copper-nickel, through the adhesive and to the vessel or hull substrate made of less noble materials.
(b) At present, there is no means for reducing the erosion rate of the copper-nickel anti-fouling sheathing. As such, excessive wear rates occur and the useful life of the foil disclosed in the patent and reissue patent is now no more than five (5) years at best.
(c) All technology, previously known, which reduces any electro-chemical corrosion also negates or significantly reduces the anti-fouling abilities of the copper-nickel metal within a 30-inch radius of any cathodic protection anode system contained in the same plane.
(d) Marine vessel transducers suffer signal strength decreases and image distortions due to unprotected electro-chemical reactions between their outer casings and the copper-nickel anti-fouling metal.
(e) Catalyzed adhesives are not used, disclosed or specified in the patent or reissue patent and such adhesives would be helpful in enhancing the effectiveness and lifetime of the applied films.
(f) The patent and reissue patent fail to disclose a complete procedure so as to appropriately apply a copper-nickel anti-fouling metallic foil through the use of pressure sensitive adhesive. As now known in the prior art, methods of applying heat sensitive adhesives using butt joints and overlap do not go far enough in providing the specific techniques which will enhance the installed lifetime of such adhesives.
(g) It is important to note that most pleasure boats are now constructed with hulls having strakes. The patent and reissue patent fail to disclose any method which could be used to properly apply the metallic foil over a marine vessel hull having such strakes.
(h) The patent and reissue patent do not discuss the length of time which it would take to install the metallic foil as disclosed therein per unit area. Applicant herein has experimented with the installation of a foil in accordance with techniques disclosed in the patent and reissue patent and has found that it takes 14 man-days to install 300 square feet of foil. This results in extremely high labor costs for the installation of the foil on a hull which render the foil and technique for its installation as disclosed in the patent and reissue patent extremely uneconomical.
(i) The patent and reissue patent fail to disclose any procedure or method to prevent the adhesive bond failures which would result from surface contamination including through the existence of oils which may form on new or used hull surfaces.
(j) Finally, the patent and reissue patent fail to disclose any method for repairing damaged foil sections while the vessel is in the water.